[Due for payment 2025-05-28] Refactor checklist workflow to use Github API instead of local git

[Julesssss]

Problem

Our App workflows contain some complexities surrounding git commit comparison that have led to edge cases and flakiness. This also makes further expansion complicated. For example we want to introduce Mobile-Expensify PRs to the release checklist.

Solution

Refactor by removing the local git solution for the deploy workflow. Checklist generation can use the Octokit compareCommits API to retrieve commit diff instead which is simpler to maintain and understand.

[melvin-bot]

Triggered auto assignment to @twisterdotcom (NewFeature), see https://stackoverflowteams.com/c/expensify/questions/14418#:~:text=BugZero%20process%20steps%20for%20feature%20requests for more details. Please add this Feature request to a GH project, as outlined in the SO.

[melvin-bot]

⚠️ It looks like this issue is labelled as a New Feature but not tied to any GitHub Project. Keep in mind that all new features should be tied to GitHub Projects in order to properly track external CAP software time ⚠️

[melvin-bot]

Triggered auto assignment to Design team member for new feature review - @shawnborton (NewFeature)